How to Play an MP4 Video on My Macby KR KnowlinUpdated September 28, 2017
With iTunes, you can play a variety of audio and video format types on your computer. ITunes comes standard on all Mac computers as the default media player. The application supports video content downloaded from the iTunes Store and Quicktime-compatible files like MOV, M4V and MP4. Add the MP4 file you want to play to your iTunes library just as you would any other compatible file type. ITunes will load the file and organize it into your media library.
Open the "File" menu.
Select "Add to Library" from the drop-down list. A dialog box will open.
Browse for the MP4 file on your Mac that you want to open.
Click on the file to select it, then click "Choose." ITunes will load the file to the "Movies" or "TV Shows" section of your iTunes library.
Double-click the file to play it in iTunes.